Dyes of the dibenzanthrone series



United States Patent 2,819,270 DYES OF THE DIBENZANTHRONE SERIES WilhelmSchmidt-Nickels, Little York, N. J.', assignor to General Aniline & FilmCorporation, New York, N. Y., a corporation of Delaware No Drawing.Application February 7, 1956 Serial No. 563,857

4 Claims. (Cl. 260-272) The invention here presented is a new type ofblack dyestufi of unusually good light stability, excellent blacknesswhich can be prepared from a single intermediate to yield a high-gradevat dyestufi.

Black vat dyestufis are known in many forms and kinds,

but they tend to be somewhat expensive it made for highest qual ty, andusually involve several essential intermediates, usually intermediatesnot available on the open market.

The present invention presents a high grade vat dyestufi of excellentlight stability, excellent fastness and easy preparation from a single,readily available intermediate. The dyestufis of the new type herepresented use as their intermediate the substance known asaminodibenzanthrone or aminoviolanthrone which is a regular article ofcommerce and readily available. It is obtained by nitration ofdibenzanthrone (violanthrone), followed by reduction. The preparation iswell shown in Centralblatt, 1929; II; 496. The method of preparation isalso well shown in French Patent No. 651,152 issued February 15, 19 29.

The process of the invention starts with aminoviolanthrone having theformula:

2,819,276 Patented Jan. 7, 1958 ice I 2 This material is treated, in ahigh-boiling solvent such as nitrobenzene, with ethylchlorocarbonate toyield the compound of the structural formula:

The bromine compound is then autoclaved with ammonia in presence of acopper catalyst to yield the desired dyestuii of the followingstructure:

This is the dyestuff of the invention giving an excellent deep blackfrom a hydrosulfite vat. It shows an excellent light-fastness and goodfastness to washing and chlorine.

The following examples -will show the detailed procedure for themanufacture of the material:

Example 1 A charge of: 640 parts by volume nitrobenzene; 62.8 parts byweight aminoviolanthrone with a nitrogen analysis of 2.81% and 63.6'parts .by volume of chloroethyl carbonate was stirred at 90-95 "Cg'for2 hours, at 130- 135" C. for 2 hours, at 150-155 C. for 2 hours andfinally at 170-175 C. .for 2 'hours. After allowing to cool to roomtemperature the reaction product was filtered off, washed withnitrobenzene, with benzene and then dried. The weight obtained was 61.4parts by weight equivalent to a yield of 93% ofithe theory of thegreyishblue vat dyestuff of the formula C H O N. Found: N=3.00%. Theoryfor C3QII1503N: N=2.82%. (The accuracy of all nitrogen analyses wasabout +0.2%.) 29.9 parts by weight of the product of the abovepreparation and 3.0 parts by weightriodiae were zintnoduced into 450parts by volume nitrobenzene. The mixture was heated to 155-160 C. Atthis temperature a solution of 12.3 parts by volume brominein 60 partsby volume nitrobenzene was dropped into the mixture under agitationduring 90 minutes. Finally, the charge was stirred at 155-160 C. for 4hours. The 'reaction mixture was allowed to cool to room temperature andfiltered. The cake was washed with nitrobenzene, with benzene and thendried. The weight obtained 'was 32.8 parts by weight equivalent to ayield of 83% of. the theory of the bluegrey vat dyestutf of the lformulaC H O NBr Found: Br=24.58%, N=2l29%. Theory for C H O NBr Br=24.43%,N=2.l4%. An autoclave was charged with 360 parts by volume 28% aqueousammonia, 24 parts by weight of the dibrorn compound pf the abovepreparation and 3 parts by weight of crystallized copper sulfate. Themixture was stirred at 200 C. for 10 hours. The reaction product wasfiltered ofl, 'washed neutral and dried. he weight obtained was 16.5parts by weight, equivalent to a yield of 88% of .the theory, of the NewVat Of the formula C35H1403N3. Found: Br=%. Theory for C H Q N N==5.49%.The product dyed cotton from a hydnosulfite vat a deep black ofexcellent light-fastness and good fastness to washing and chlorine.

Example 2.-Preparatr'on of the leum sulfuric acid ester *sa'lt dfth'eVar Black dfiflxdmfle! 12.1 parts by weight .of .the -iBlaok;prmared .asdescribed in Example 1 was introduced at 48 C. into a salted out by theaddition of sodium chloride.

mixture of parts by volume of pyridine and 12 parts by volume ofchlorosnlfonic acid. After of "8 parts by weight of iron by hydrogen and0.2 part by weight of cuprous chloride the charge was stirred in anatmosphere of carbon dioxide gas for 4 hours at 5355 C. The reactionproduct was poured into a solution of 40 parts by weight of sodiumcarbonate in 240 parts by volume of water. After removal of the pyridineby distillation under diminished pressure the aqueous leuco ester saltsolution was filtered off the iron sludge and The product printed cottongrey by the conventional methods.

By the process of the invention there is thus obtained a new dyestutfhaving the constituh'on as above indicated which gives a black ofexcellent light-fastness and good fastness to chlorine and washing. Itis easily made from a relatively inexpensive intermediate and is inevery way a desirable dyestuif.

While "there-are above disclosed but a limited number of embodiments ofthe process of the'invention it is possible tuprovide still iothercnibodiments :without dqaarting from tbe'inventive .coneeptherein-disolosed; audit is therefore desired that only such limitationsbe imposed upon the appended claims as are stated therein tor rrequiredby the prior art.

The invention claimed is:

1. A black dyestu'ff having the structural formula:

2. A black dyestuflf having the structural formula prepared by reactingan aminoviolanthrone having a nitrogen content within the range between2.5% and 3.5% with chloroethyl carbonate, brominating the resultingproduct to produce a dibrom derivative and autoclaving the derivativewith aqueous ammonia in the presence of a copper catalyst.

3. A black dyestuff having the structural formula prepared by reactingan aminoviolanthrone having anitrogen content within the range between2.5% and 3.5% with chloroethyl sulfonic acid, brominating the resultingproduct to produce a dibrom derivative and autoclaving the derivativewith aqueous ammonia in the presence of a copper catalyst the saiddyestufi being in the form of the leuco-sulfuric acid ester salt.

4. A method for preparing a black dyestuif having a structural formulacomprising the steps in combination of mixing together 640 parts byvolume of nitrobenzene, 62.8 parts by weight of aminoviolanthrone and63.6 parts of chloroethyl carbonate, stirring the mixture for two hoursat 90-95 C.; at two hours more at 130-135 C. and for an additional twohours at 170175 0.; thereafter cooling to room temperature filtering outthe solid reaction product mixing together 29.9 parts by weight of thereaction product with 3 parts of iodine and 450 parts of nitrobenzene;heating the mixture to a temperature of about 155-160 C. and addingthereto a solution of 12.3 parts of bromine in 60 parts nitrobenzene,and thereafter stirring the mixture for four hours at 155-160" C.filtering out the reaction product and autoclaving 24 parts of thesecond reaction product with 360 parts of aqueous ammonia and threeparts of crystallized copper sulfate.

Great Britain May 26, 1954

1. A BLACK DYESTUFF HAVING THE STRUCTURAL FORMULA: